“Since 1992,” the updated notice states, “with the exception of stabilizing the stratospheric ozone layer, humanity has failed to make sufficient progress in generally solving these foreseen environmental challenges, and alarmingly, most of them are getting far worse.”

Among the stated threats in the original article was this: “Our massive tampering with the world’s interdependent web of life—coupled with the environmental damage inflicted by deforestation, species loss, and climate change—could trigger widespread adverse effects, including unpredictable collapses of critical biological systems whose interactions and dynamics we only imperfectly understand.”

Half-Earth is addressing this challenge directly. During the inaugural Half-Earth Day held October 23, 2017, in Washington, D.C., scientists led by Dr. Wilson agreed that saving half the Earth was not only necessary, but well within our powers to achieve. Leading with detailed species richness and rarity mapping, the Half-Earth Project is providing the foundation for reaching this global goal, and the scientific leadership needed to address the threat stated in the “Second Notice.” Progress is being made, but much remains to be done.

“To those who are steering the growth of nature reserves worldwide, let me make an earnest request:” Dr. Wilson implores. “Don’t stop. Just aim a lot higher.”